Hi Fabien,
Quinoprotein methanol dehydrogenase was supposed to contain only one
subunit when it was discovered.
Then 3D structure determination indicated the presence of a second,
small subunit.
See Nunn, Day & Anthony, Biochem J. 1989 June 15; 260(3): 857–862.
Perhaps this is relevant.
HTH,
Fred.
Fabien Bergeret wrote:
> Hello
>
> We’re resolving a structure of a soluble protein and in the electronic
> density map (maximum resolution at 2.2Å), we observe a supplementary
> density that does not belong to the protein. This density is present
> in two different crystalline forms obtained in different
> crystallization conditions.
> This density could be represented by an oligopeptide ~10 residues long
> for which there is no ambiguity about its polarity. Furthermore, side
> chains are quite easily visible and a sequence can therefore be assigned.
> The deduced sequence doesn’t belong to the sequence of the protein of
> interest, meaning that the oligopeptide has been co-purified and
> co-crystallized.
>
> Has somebody met a similar situation? Could you please give us some
> advices in terms of refinement, validation, etc.?
>
> Thanks in advance
>
> Best regards
>
>
> Fabien
> PhD student
> [log in to unmask] <mailto:[log in to unmask]>
>
>
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